As conventional hand dryers, for example, Japanese Patent Application Laid-open No. 06-62981 discloses a hand dryer that includes: a hand inserting unit that is provided such that hands can be inserted by opening the front surface and the side surfaces of a box body; outlet nozzles arranged in the upper and lower surface portions of the hand inserting unit; a high-pressure-air generating unit that draws air in the hand inserting unit and sends high pressure air to the outlet nozzles; and a sensor that is provided in the hand inserting unit and detects the insertion state of hands in the hand inserting unit. More specifically, it is disclosed that the hand inserting unit is sloped toward a lower portion so as to have a substantially U-shape, the sensor is composed of inlet upper-and-lower-side sensors provided on the inlet side in the upper and lower surface portions of the hand inserting unit and deep upper-and-lower-side sensors provided on the deep side in the upper and lower surface portions of the hand inserting unit, when hands are inserted as far as a position connecting between the deep upper-and-lower-side sensors, a hand detection signal is sent to a control circuit and the high-pressure-air generating unit is started, and, when hands are not detected by the inlet upper-and-lower-side sensors, the high-pressure-air generating unit is stopped.